如果x^2+xy+y-14,y^@+xy+x=28,求x+y的值.

如果x^2+xy+y-14,y^@+xy+x=28,求x+y的值. 如果xy/x+y=2,那么3x-5xy+3y/-x+3xy-y=? x^2-xy/xy-y^2约分 作乘法:(x+y)(x^2-xy+y^2)；(x-y)(x^2+xy+y^2)如果能因式分解更好 如果x+y=-根号3 xy=-2那么x^2y+xy^2= 如果x+y=0,xy=-7,则x^2y+xy^2=? 如果X+Y=10 XY=7则X~2Y+XY~2=? 如果x-y＝2,xy=3,则x²y-xy²=几 如果x²+xy=2,y²+xy=7 求x²-y² 如果x+y=0,xy=2,求x³y-xy³的值 5x^2y-3xy^2+4xy-14xy^2+4xy-2x^2y（化简） 2x²y-3(2xy-xy)-xy （x^2+xy/x-y)/（xy/x-y)计算 若x^2+xy+y=14,y^2+xy+x=28,求x+y (x^2+2xy+y^2-4xy)*(x^2-2xy+y^2+4xy) .(x+y-2)(x+y-2xy)+(xy-1)^2 (x^2-xy)y÷y-x/xy怎么做? |x|/x+y/|y|+xy/|xy|=